Effect of carbenoxolone on alkaline secretion by isolated amphibian gastric and duodenal mucosa.
The influence of carbenoxolone sodium on HCO-3 transport has been examined in spontaneously alkalinizing amphibian antral (Necturus and Rana catesbeiana) and proximal duodenal (Rana catesbeiana) mucosa and in cimetidine-treated fundic mucosa (Rana temporaria) in vivo. Low concentrations of carbenoxolone (10(-6)-10(-4) mol/l, serosal side and 10(-5) mol/l, luminal side) did not affect the secretory rate or electrical properties of these tissues. In the stomach a higher concentration of carbenoxolone (10(-3) mol/l, serosal side) caused an immediate fall in transmucosal potential difference (PD) and electrical resistance. There was an initial decrease in the rate of HCO-3 transport followed by an increase in titratable alkalinization due to passive permeation of base from the serosal bathing solution. The non-steroidal anti-inflammatory agent ibuprofen (3 x 10(-3) mol/l, serosal side) inhibited alkaline secretion while the bile salt sodium taurocholate (10(-4) mol/l, luminal side) converted net alkaline secretion to a titratable acidity in cimetidine-treated fundus. Pretreatment of the mucosa with carbenoxolone (10(-4) mol/l) did not influence the response to taurocholate but when added with ibuprofen it potentiated the inhibitory effect of this drug on fundic alkaline secretion. In contrast, prostaglandin E2 (10(-6) mol/l) markedly reduced the inhibition of fundic alkaline secretion caused by ibuprofen. The anti-ulcer properties of carbenoxolone do not appear to be related to effects on gastroduodenal HCO-3 transport.
D000818:Animals; D001639:Bicarbonates / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002229:Carbenoxolone / Q000494:pharmacology*; D002927:Cimetidine / Q000494:pharmacology; D015232:Dinoprostone; D004386:Duodenum / Q000187:drug effects; D005753:Gastric Mucosa / Q000187:drug effects* / Q000378:metabolism; D006034:Glycyrrhetinic Acid / Q000031:analogs & derivatives*; D007052:Ibuprofen / Q000494:pharmacology; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000378:metabolism; D009337:Necturus; D011458:Prostaglandins E / Q000494:pharmacology; D011892:Rana catesbeiana; D011896:Rana temporaria; D013656:Taurocholic Acid / Q000494:pharmacology
D001639:Bicarbonates; D011458:Prostaglandins E; D013656:Taurocholic Acid; D002927:Cimetidine; D015232:Dinoprostone; D002229:Carbenoxolone; D006034:Glycyrrhetinic Acid; D007052:Ibuprofen